Patients often have open wounds that must be cleaned of dirt and other foreign particles before closing. Sometimes wounds must be cleaned several times. In known wound cleansing procedures, a stream of sterile cleansing fluid is directed through a nozzle at the wound. Wound cleansing solutions, well known in the art, generally are saline solutions, typically 0.9% sodium chloride. When a cleansing solution is not to be used within a matter of hours, a preservative such as benzalkonium chloride may be included. Additives such as buffers may be included as well. If the stream impacts the wound within a limited pressure range of about 8-15 psig, the pressure stream dislodges foreign particles in the wound and washes them away, but does not tear away living tissue. It is also known to use fluid streams at substantially lower or higher pressures.
Several systems and devices for delivering a stream of fluid to a wound are known. Some systems are fixed installations. See, e.g., U.S. Pat. Nos. 3,912,168, 4,692,140, and 4,635,621. Others utilize "portable" dispensers; that is, dispensers that can be carried by hand to the patient without being attached either to a separate power supply or to a fluid supply. Typically a wound requires upwards of 200 ml of fluid to be cleaned properly.
One known apparatus of the fixed installation type consists of a syringe with a flexible plastic tip for aiming the fluid stream. One end (sharpened) of a tube attached to the syringe is spiked into an IV bag, a source of cleansing fluid. As the syringe piston is retracted by the care giver, the syringe fills with cleansing liquid. When the care giver presses on the piston, the liquid is forced out the flexible plastic tip. A rigid splash shield may be positioned on the syringe near the tip to prevent splashback onto the care giver. This device has several disadvantages. It requires the care giver to remain near the fluid supply, the IV bag, because the syringe, which holds only 10 or 30 cc of fluid, remains attached to the IV bag during use. The care giver must pump repeatedly with his thumb to clean a single wound. The pressure of the liquid stream is not fixed. Rather, it depends on the thumb pressure applied to the piston by the care giver. If the care giver does not depress his thumb with enough force, the pressure of the stream will be insufficient to dislodge particles.
Another fixed installation commercially marketed is the Pulsavac.RTM., manufactured by Bristol-Myers Squibb Co., purportedly under U.S. Pat. Nos. 4,555,645; 4,561,431; 4,635,621; and 4,692,140. This apparatus includes an electric pump that delivers wound cleansing liquid through a long, flexible tube to a hand-held dispensing gun. Another tube (sharpened) attached to the pump is spiked into a bag of wound cleansing solution. The pump is capable of delivering liquid in a pulsing manner (adjustable to a maximum pressure of 70 psig) through the delivery tube to the dispensing gun. The care giver holds the gun and "shoots" cleansing fluid at the wound. The dispensing gun comes with several attachments, including a spray shield that attaches to the tip of the gun. The shield consists of an inner flexible cone and, optionally, an outer rigid cone. The cones trap fluids exiting the wound between them so that they can be removed by a vacuum tube mounted in the gun.
This apparatus has several disadvantages. The dispensing gun must be used near the pump because of the delivery and vacuum tubes. Further, the tubes, if of appreciable length, drag across the floor, generally a hospital floor. Also, the apparatus creates considerable medical waste. After each use, the entire gun/spray shield combination is discarded. The pump and tubes must be disposed of after 24 hours.
Aerosol dispensers are known for use as portable dispensers of wound cleansing solution. Two commercially available dispensers are the Dey-Wash.RTM. aerosol sprayer marketed by Dey-Wash Corporation and the Baxter Skin Wound Cleanser marketed by Baxter Healthcare Corporation. Both utilize rigid aerosol cans. The Dey-Wash aerosol can contains a bag filled with cleansing liquid. The aerosol dispensers are operated in the conventional manner. A straw may be fitted onto the outlet of the nozzle to help direct the fluid.
Aerosol dispensers overcome one major disadvantage of fixed installations, namely, lack of portability. However, they also have distinct disadvantages. They create considerable medical waste. For the available aerosol systems described above, a dispenser is used only on a single patient, after which the can, other parts and materials become waste. An empty aerosol dispenser is just as large as a full one, so the volume of waste is large. Aerosol dispensers may have other disposal problems, as is well known, including the problem that metal aerosol cans can not be incinerated. The noted commercially available aerosol devices do not come with a splash shield, so contaminated or infected fluid may splash onto the care giver and the dispenser. Another drawback to this device is that the care giver cannot determine visually how much wound cleansing solution remains in the container. With the commercially available aerosol dispensers, the care giver cannot adjust the force with which the fluid is dispensed. Importantly, the stream pressure is not as nearly constant as desirable as the dispenser is emptied.
It is an object of this invention to provide a wound cleansing apparatus having the advantage of the aerosol dispensers, namely, portability, without the disadvantages of those dispensers.
It is another object of this invention to provide a portable wound cleansing apparatus capable of delivering a liquid stream of wound cleaning fluid at a substantially constant pressure of 8 psig and, optionally, at that pressure and at additional pressures selected by the care giver.
It is yet another object of this invention to provide a wound cleansing device that also protects the care giver from fluid splashing off the wound.
It is yet another object of this invention to provide a portable wound cleansing device which provides visual indication of how much wound cleansing liquid remains in the device.
It is yet another object of this invention to provide a portable wound cleansing device that minimizes medical waste and, further, produces a type of waste with minimal disposal problems.
It is yet another object of this invention to provide a portable wound cleansing device that can be operated with conventional nozzles that are readily commercially available to provide wound cleaning solution at a controlled pressure.
It is yet another object of this invention to provide an improved portable wound cleansing device that is sterile, so that it may be used in sterile fields, such as hospital emergency rooms and operating rooms.
These and other objects of the invention will become apparent to those working in the art by reference to the following description, including the accompanying drawings.